Pressure reducer and air strainer



Dec. 12, 1950 F. H. ANDERSON 2,533,907

PRESSURE REDUCER AND AIR STRAINER Filed March 19, 1949 MAIN RESERVOIR AIR SUPPLY 5 ":Ilm

To TANK Egg;

INLET RESERVOIR 28 Patented Dec. 12, 1950 UNITED STATES PATENT O Fl-FICE JPRESSURE REDUCER AND AIR Frank H. Anderson, Minneapolis, Minn.

Application March :19, 1949, Serial No. 82,403

2 Claims. '1

Under Interstate Commerce-'Gommission orders each steam locomotive must be equipped with a tank water level indicator to show on a gauge, that is readily visible in the cab of the locomotive, the height of water in the tender tank. Many of these indicators operate by air pressure acting against the head of water in a pipe extending down to within about 2" of the bottom {of the tender tank and open at its lower end. The higher the water in the tank the greater the pressure required to force air down through the pipe to escape at the lower end and bubble up through the water. That pressure on a suitable gauge will indicate the depth of the water in.

feet and inches.

Many large tender tanks, when full of water, have a depth on the order of eight feet, and hence present a hydraulic head, in the mentioned pipe, on the order of three and one-half pounds. The source of compressed air on the locomotive is the main reservoir with a pressure of one hundred and forty pounds, which pressure must be reduced to less than five pounds and delivered to a certainty, regardless of the unavoidable presence of oil, dirt, etc, in the compressed air.

Pressure reducers and air strainers heretofore used in these devices have been the cause of a great deal of difiiculty and expense; and the principal object of this invention is to provide a suitable device that will be substantially free from those objections. Generally speaking, this is accomplished by providing a pressure reducer and air strainer including an orifice and a operating pin or needle, to reduce that orifice to the correct size, and to automatically clean it by the operation of removing or inserting a pin or needle.

In the drawings:

Fig. 1 is a diagram of a portion of a tender, a gauge on the locomotive, a pressure reducer, air strainer embodying this invention, and appropriate pipe connections;

Fig. 2 is an enlarged section through the pressure reducer and air strainer in assembled condition;

Fig. 3 is a similar section of the body portion of that device and Fig. 4 is a similar section through a clean-out plug and clean-out needle that has been found satisfactory.

In Fig. 1 the tender is indicated by W, equipped with a pipe I I open at its lower end to the water in the tender tank, and flexibly connected at [2 to a pipe 13 leading to a pressure reducer and air strainer, generally indicated at I4, connected to .51 the main reservoirof .air supply by a pipe [5 and toagauge l 6 by a pipe .I I.

The pressure reducer and air strainer includes a valve body, generally indicated ,by 18, having a pipe-threaded high pressure inlet 49, a pipethreaded low pressure outlet .29, and a pipethreaded outlet .21 to the gauge 16. It also includes a high pressure chamber 22 ending in a clean-out opening 23, threaded at 26 to receive a clean-out plug 25. In use the chamber 22 is filled with cotton waste and serves as a primary strainer.

The valve body l8 has a central bore 26 forming a low pressure chamber or passage extending vertically through it from the high pressure chamber to the outlet 2|. It is connected with the outlet to the tank 20 by a port 21. The high pressure inlet [9 is connected to the high pressure chamber by a similar port 28.

The low pressure passage 26 extends downwardly into a cylindrical column 30, and is there connected with the high pressure chamber through a reducing orifice 3!. That orifice is much larger than is necessary to pass the appropriate amount of air, and is reduced to the correct dimensions by a pin or needle 32 carried by the clean-out plug 25 and extending through the orifice, substantially as indicated in Fig. 2.

In the form that has been found satisfactory in use, the low pressure chamber or passage 26 and the ports 2! and 2B are formed with a drill. The orifice 3| is formed with a 5 drill, reamed out with a piece of No. .14 gauge (.033" diameter music wire) having one end groun to a chisel edge having a angle. The wire is set in the chuck of a drill press and used after the fashion of a reamer in the orifice formed by the 5 drill.

The clean-out needle or pin 32 is made of No. 14 gauge music wire (.033" in diameter). If it slides easily in the orifice the latter has been enlarged too much. The clearance is right when not more than twelve bubbles per second pass through the outlet pipe to the tender when its end is inserted in water contained in a quart milk bottle.

The needle or pin 32 is made fast to the cleanout plug 25 by bending over its end portion 34, as indicated in Figs. 2 and 4, and making it fast by solder 35.

In the assembly shown the pressure from the main reservoir to the pipe l5 enters the inlet l9, goes through the port 28 into the high pressure chamber 22, filters through the orifice 3| into the passage 26, thence through the pipe I! to the gauge l6, and through the orifice 27 and the pipe I3 and connection M2 to the pipe II in the tank.

The minute passage around the needle or pin 32 through the nozzle 3| reduces the one hundred and forty pounds pressure to something less than five pounds, and also serves as a strainer for any dirt, grease, etc., that may be entrained in the air. Any tendency to clog is cleared by the simple operation of screwing the c1ean-out plug out and in. This operation is performed at regular testing intervals.

I claim as my invention:

1. In a pressure-reducing valve for efiecting large reductions in gas pressures, a valve body having inlet and outlet openings with a reducing orifice intermediate said openings, said reducing orifice having at least a portion thereof of circular cross section, and a throttling and clean-out needle of substantially uniform, circular, crosssectional area normally occupying and. projecting through said circular portion of the orifice, said needle being of a diameter substantially equal to the diameter of said circular orifice portion, and fitting into said orifice with a near tight fit, whereby the effective size of the orifice is defined by the infinitesimal area of the annular space between the needle and the orifice, and means for rotating said needle within said orifice.

H 2. In a pressure-reducing valve for effecting large reductions in gas pressures, a valve body having inlet and outlet openings with a reducing orifice intermediate said openings, said-reducing orifice having at least a portion thereof of circular cross section, and a throttling and clean-out needle of substantially uniform, circular, crosssectional area normally occupying and projecting through said circular portion of the orifice, said needle being of a diameter substantially equal to the diameter of said circular orifice portion, and fitting into said orifice with a near tight fit, whereby the effective size of the orifice is defined by the infinitesimal area of the annular space between the needle and the orifice, and means for rotating said needle within said orifice, said last-named means including a plug screwed into the body and rigidly secured to one end of said needle.

FRANK H. ANDERSON.

REFERENCES CITED The following references are of record in the file of this patent:.

UNITED STATES PATENTS 7 

